Mitth'raw'nuruodo, better known as Thrawn, was a Chiss male Grand Admiral working for the Galactic Empire. A somewhat unconventional Imperial and accomplished tactician, Thrawn favored things such as art and was a major advocate of the TIE Defender project. After the Grand Inquisitor and even Darth Vader failed to put an end to growing rebellion on the planet Lothal, Thrawn was sent to deal with them, effectively finding the rebel base on the planet Atollon and driving away the Rebel Alliance, and in the process uncovered Agent Kallus as a rebel spy. Thrawn was eventually defeated when he and Lieutenant Commander Ezra Bridger were carried into hyperspace by wild purrgils. While both survived, neither has been seen since. Thrawn's knowledge of the Unknown Regions later greatly helped the reorganization of the Imperial Navy into the First Order.

The official description and box art for 75170 The Phantom refers to Thrawn as "Admiral Thrawn", whereas in the Star Wars Rebels, Thrawn holds the significantly higher rank of Grand Admiral. Thrawn's minifigure also features an incorrect insignia, showing an Admiral's rank instead of a Grand Admiral's. This may indicate that the minifigure is based on concept art for Thrawn's appearance in Star Wars Rebels, where he was drawn with an Admiral's insignia and referred to only as an Admiral.

Thrawn's real name, Mitth'raw'nuruodo, is difficult for humans to pronounce, which is why he, like many of his fellow Chiss, uses his "core name", Thrawn.

Thrawn personally knew Jedi Knight Anakin Skywalker but did not recognize him under his famous armor years later as the Sith Lord Darth Vader.